iRoot BP修复磨牙髓室底穿孔的研究

目的 探讨iRoot BP直接修复髓室底穿孔的效果。方法 收集新鲜拔除的人恒磨牙40颗,其中36颗于髓室底中央制备直径2 mm的穿孔洞型,随机分为A、B组,每组18颗,分别用iRoot BP和矿物三氧化聚合体（MTA）修复髓室底穿孔;另外4颗为对照组,只开髓不制备髓室底穿孔。从A、B组中各随机选择3个样本用扫描电子显微镜观察材料和牙本质的结合界面;其余15个样本用葡萄糖氧化酶-蒽酮法检测微渗漏值。结果 A组中,iRoot BP与牙本质结合较为紧密,而B组中MTA和牙本质之间存在不均匀的微小间隙。在观察期内,B组的微渗漏值高于A组,其差异有统计学意义（P<0.05）。结论 iRoot BP修复髓室底穿孔的封闭效果优于MTA。     

4种窝沟封闭剂微渗漏及抗压强度的比较实验

目的:比较4种窝沟封闭剂的微渗漏及抗压强度,为临床选择使用提供实验室依据.方法:收集12 ～16周岁志愿者因正畸治疗需要而新鲜拔除的前磨牙28个,并将其随机分为A、B、C、D4组(n=7),分别用Helioseal F、VOCO Fissurit F、AscentTM和ClinproTM封闭(牙合)面及颊、舌侧窝沟;冷热循环100次后,分别从每组中各随机抽取5个用20 mg/L的亚甲蓝染色检查微渗漏;所余2个用扫描电镜观察窝沟封闭剂与牙体组织结合界面及两者之间的密合度.取4种窝沟封闭剂分别制作直径4 mm,厚4 mm的盘状标本各9个,置于生理盐水中37℃下浸泡.分别于浸泡后ld、28 d、63 d后测定各标本的抗压强度(n=3).结果:4种封闭剂之间微渗漏评分均无显著性差异(P＞0.05);扫描电镜观察显示,VOCO Fissurit F与牙釉质完全结合在一起,并渗透到窝沟底部,Helioseal F、AscentTM、ClinproTM虽与釉质结合较紧密但窝沟底部的封闭剂中有气泡或断裂.4种封闭剂中AscentTM组3个时间点的抗压强度均高于其他3组(P＜0.05),而另3组各时间点内两两相比均无统计学差异(P＞0.05).结论:VOCO Fissurit F的边缘密合性相对较好;AscentTM的抗压强度较高.     

三种方法修复薄弱根管冠方微渗漏的体外评价

目的评价可塑型纤维桩、预成纤维桩及根管重塑后预成纤维桩修复薄弱根管后的冠方微渗漏情况。方法选择正畸拔除上颌第一前磨牙36颗,制备形成薄弱根管。将30颗样本牙随机分为3组,A组可塑型纤维桩核系统修复、B组根管重塑后预成纤维桩核系统修复,C组预成纤维桩核系统修复,另外6颗为对照组。所有样本进行5℃-55℃冷热循环5000次后,置于0．5％碱性品红溶液中24h。将试件纵向剖开为2部分,在体视显微镜下观察各剖面修复材料与根管壁之间的微渗漏情况。用Kruskal—Wallisf法进行统计分析。结果3种方法修复后修复材料与根管牙本质之间均存在微渗漏现象,3组间无统计学差异（P〉0．05）。结论在本实验条件下,3种方法修复薄弱根管对冠方微渗漏的影响相近。     

Evaluation of microleakage of root canal fillings irradiated with different output powers of erbium,chromium:yttrium‐scandium‐gallium‐garnet laser

This study evaluated the root canal seal achieved by irradiation with an erbium, chromium:yttrium‐scandium‐gallium‐garnet laser, and the optimal output power to remove debris and the smear layer were determined. One hundred mandibular premolar teeth were prepared and divided into four groups. Group 1 was not lased but was irrigated with 5 mL of 5.25% NaOCl and 5 mL of 17% ethylenediaminetetraacetic acid. Group 2 was irradiated at a panel setting of 1 W, group 3 at 2 W and group 4 at 2.5 W, with a 50% water level and 48% air‐cooling level. Root canals were obturated by cold lateral compaction, and apical microleakage was measured using a fluid filtration model. The remaining debris and smear layer were evaluated via scanning electron microscopy. Statistically significant differences were detected between groups. Irradiation at 1 and 2 W using an erbium, chromium:yttrium‐scandium‐gallium‐garnet laser produced a seal superior to that of the other treatments.     

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目的对比4种充填材料的边缘微渗漏情况,为其临床应用提供合理指导。方法选择2013年1—6月青岛大学医学院附属医院口腔科因牙周病或阻生齿而拔除的健康新鲜后牙60颗,备洞后随机分为6组,每组10颗,分别使用Fihek Z250复合树脂（A1、A2组）、Ketac N100树脂加强型玻璃离子（B1组）、Ketac MolarEasymix型玻璃离子（B2、B3组）、F2000Compomer玻璃离子复合体（B4组）充填窝洞。其中A2组充填后充填体表面涂布AdperSingleBond2粘接剂,B3组充填后充填体表面涂布凡士林,而其他各组充填后表面不做任何处理。经冷热交替实验后,记录各组染料渗入窝洞壁与充填体之间的深度,并进行统计分析。结果A2组微渗漏最小,B2组微渗漏最大,与其他组（A1、B1、B3、B4）相比差异有统计学意义（P〈0．05）;A1、B1、B3、B4组间两两比较差异均无统计学意义（P〉0．05）。结论复合树脂、树脂加强型玻璃离子、玻璃离子复合体的边缘微渗漏均小于传统型玻璃离子;表面涂布隔湿剂后能增强上述材料的边缘封闭性能。     

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目的评价4种黏结剂对氧化锆全瓷嵌体边缘微渗漏的影响。方法选取2012年8月佛山市禅城区向阳医院口腔科新鲜拔除的上颌第三磨牙40颗,随机分为A、B、C、D组,每组10颗,制备V类洞形。4组离体牙分别采用全酸蚀黏结剂AdperSinglebond2（A组）及自酸蚀黏结荆ClearFilSEBond（B组）、MultilinkSpnnt（C组）和AdperEasyOne（D组）黏结氧化锆全瓷嵌体,修复后离体牙经冷热循环后行2％亚甲基蓝染色,根管显微镜下观察各组微渗漏程度并进行比较。结果在铪壁,c组微渗漏明显高于A和B组,差异均有统计学意义（P〈0．05）;但与D组差异无统计学意义（P〉0．05）。在龈壁,c组微渗漏明显高于其他3组,差异均有统计学意义（P〈0．05）;而其他3组之间差异均无统计学意义（P〉0．05）。结论自酸蚀黏结剂ClearFilSEBond和AdperEasyOne的封闭能力较好,且较全酸蚀黏结剂操作简单方便,推荐临床使用。     

不同树脂嵌体材料边缘微渗漏的对比研究

目的：通过对比4种树脂嵌体材料的微渗漏大小,为临床树脂嵌体材料的选择提供参考.方法：40颗离体牙按嵌体备洞原则制备近中邻（牙合）Ⅱ类洞,随机分为4组,每组10颗.分别用Z350、P60、Ceramage、Solitaire 2制作嵌体后使用Adper Single Bond 2和Adper Rely X ARC进行粘结.经冷热循环500次品红染色后,金刚砂片平行于牙体长轴沿近远中方向将修复体纵向剖开2次,在体式显微镜下测量染料渗入轴壁、龈壁的深度.结果：4组树脂嵌体材料轴壁和龈壁均出现微渗漏.经单因素方差分析,不同树脂嵌体材料之间的轴壁（F=0.131）及龈壁（F=0.385）微渗漏差异无统计学意义（P＞0.05）;同材料组的龈方渗漏程度均显著高于轴壁,配对t检验显示差异有统计学意义（P＜0.01）.结论：从微渗漏深度大小来进行评价,4种树脂嵌体材料均是临床上制作树脂嵌体理想的材料;树脂嵌体与牙釉质粘结效果比牙本质好.     

Microleakage of self-etch primer/adhesives in endodontically treated teeth

BACKGROUND: The authors evaluated the coronal marginal leakage of endodontically treated teeth bonded with four self-etching adhesives and one total-etch adhesive system. MATERIALS AND METHODS: The investigators prepared Class II cavities in 60 extracted human premolars. They performed conventional endodontic therapy using a resin-based sealer and gutta-percha points. They randomly assigned each tooth to a group receiving one of the following adhesives: Adper Prompt L-Pop (3M ESPE, Seefeld, Germany), Clearfil SE Bond (Kuraray, Osaka, Japan), FL Bond (Shofu, Kyoto, Japan), Single Bond (3M ESPE) or Xeno III (Dentsply De Trey, Konstanz, Germany). They restored all teeth with resin-based composite material (Z250, 3M ESPE). Specimens underwent thermocycling and dye penetration and were sectioned longitudinally. The authors photographed the sections under a stereomicroscope. They transferred the images to an IBM-compatible personal computer for quantitative assessment of dye penetration using image analysis software. They analyzed data by means of Kruskal-Wallis and Mann-Whitney U tests (P = .05) and evaluated two specimens from each group under scanning electron microscopy. RESULTS: None of the tested self-etch adhesives completely eliminated microleakage. Dye leakage was restricted to the coronal cavity walls; it did not migrate toward the pulp chamber or toward the root canal. Single Bond and Clearfil SE Bond showed significantly lower dye penetration values at occlusal and gingival margins. CONCLUSIONS: The coronal sealing performance of the tested self-etch adhesive systems in endodontically treated teeth was material-dependent. The use of Clearfil SE Bond in such teeth can help achieve a marginal seal comparable to that achieved with Single Bond.     

Physico-Chemical Investigation of Endodontic Sealers Exposed to Simulated Intracanal Heat Application: Hydraulic Calcium Silicate-Based Sealers

The aim of this study was to gain information about the effect of thermal treatment of calcium silicate-based sealers. BioRoot RCS (BR), Total Fill BC Sealer (TFBC), and Total Fill BC Sealer HiFlow (TFHF) were exposed to thermal treatment at 37 °C, 47 °C, 57 °C, 67 °C, 77 °C, 87 °C and 97 °C for 30 s. Heat treatment at 97 °C was performed for 60 and 180 s to simulate inappropriate application of warm obturation techniques. Thereafter, specimens were cooled to 37 °C and physical properties (setting time/flow/film thickness according to ISO 6876) were evaluated. Chemical properties (Fourier-transform infrared spectroscopy) were assessed after incubation of the specimens in an incubator at 37 °C and 100% humidity for 8 weeks. Statistical analysis of physical properties was performed using the Kruskal-Wallis-Test (P = 0.05). The setting time, flow, and film thickness of TFBC and TFHF were not relevantly influenced by thermal treatment. Setting time of BR decreased slightly when temperature of heat application increased from 37 °C to 77 °C (P < 0.05). Further heat treatment of BR above 77 °C led to an immediate setting. FT-IR spectroscopy did not reveal any chemical changes for either sealers. Thermal treatment did not lead to any substantial chemical changes at all temperature levels, while physical properties of BR were compromised by heating. TFBC and TFHF can be considered suitable for warm obturation techniques.